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Scientists comment on a 7.7 magnitude earthquake that has hit central Myanmar.
Dr Christian Málaga-Chuquitaype, Senior Lecturer, Department of Civil and Environmental Engineering, Imperial College London, said:
“I visited Thailand just over a year ago to deliver a keynote at their first national earthquake engineering conference. The fact that this was their first such event hints to the low level of awareness of earthquake hazards in engineering practice in the country. I remember that at the conference, a new seismic hazard map for Thailand was presented, and that it received a lukewarm response from practicing engineers.
“In fact, earthquakes were once considered extremely rare in Bangkok, so most buildings were not designed for seismic safety. Thailand’s first seismic code was introduced in 1997, but it applied only to certain regions—not Bangkok. A 2007 revision included Bangkok but lacked detailed seismic design rules. A more comprehensive standard was finally issued in 2009, meaning many older buildings do not meet modern earthquake safety requirements.
“Even though Bangkok is far from active faults, its soft soil amplifies the shaking, this affects especially tall buildings during distant earthquakes! With some Thai colleagues, we recently studied 98 buildings in Thailand to assess their response before and after the 2009 seismic code. We found striking differences between how these buildings were assumed to vibrate (by codes) and how they actually do so.
“Adding to the concern, Thai construction practices favour ‘flat slabs’ and post-tensioning in tall buildings together with the use of very slender columns. A ‘flat slab’ system is a way of constructing buildings where floors are made to rest directly on columns, without using beams —Imagine a table supported only by legs, with no extra horizontal supports underneath, that’s how a flat slab looks. While this design has cost and architectural advantages, is performs poorly during earthquakes, often failing in a brittle and sudden (almost explosive) manner. From the shared footage, the collapsed building in the video follows this very problematic design and combines it with extremely slender columns that are more prone to failure. A thorough forensic analysis is needed, but this building type is no longer recommended in earthquake-prone areas.”
Dr Roberto Gentile, Assistant Professor in Catastrophe Risk Modelling, University College London (UCL), said:
“The dramatic collapse of a tall building under construction in Bangkok requires particular attention, considering that Bangkok is nearly 1000km away from Mandalay. Constructing on deep, very soft-soils and/or a “basin effect” of the underlying geological features may be potential causes of ground-motion amplification experienced by tall buildings. These conditions are well documented for Bangkok, and therefore I assume that other tall buildings in the city may require a thorough assessment.”
Dr Rebecca Bell, Reader in Tectonics at Imperial College London, said:
“The 28th March 2025 Mw 7.7 that struck the near Mandalay, Myanmar has a focal mechanism consistent with a strike-slip (side-to-side) fault motion. Given the distribution of high intensity shaking reported by the USGS [1] it looks likely the earthquake occurred on a north-south trending fault, which potentially could be the Sagaing Fault.
“The tectonics of Myanmar involve subduction of the Indian tectonic plate in the west which forms the Sunda megathrust subduction zone. Myanmar marks the most northern extent of this subduction zone. Rupture of a section of the Sunda megathrust was responsible for the 2004 Sumatra-Andaman Mw 9.1 and devastating Indian ocean tsunami.
“The subduction below Myanmar is very oblique- the oceanic plate is sliding under Myanmar with a lot of side-ways motion- directed to the north at 3-4 cm/yr. To accommodate all this side-ways motion faults have formed that allow tectonic plate slithers to move sideways. These faults are called transform faults, and the Sagaing Fault is one of them. This is the same type of motion that is seen on the famous San Andreas Fault in California. The Sagaing fault is very long, 1200 km, and very straight. The straight nature means earthquakes can rupture over large areas- and the larger the area of the fault that slips the larger the earthquake. There have been six magnitude 7 or greater earthquakes in this region in the last century. Earthquakes on transform faults within continents can be particularly destructive as the earthquake rupture can be very shallow, causing a lot of shaking at the surface, and their continental nature means population centres can be located very close to the fault.”
Dr Ian Watkinson, Department of Earth Sciences at Royal Holloway, University of London, said:
“Little is known about the extent of damage in Myanmar at present after the earthquake happened , though there are reports already about building collapse in Bangkok, 1000 km from the epicentre. However, Mandalay, close to the epicentre, is a large sprawling city which has experienced significant growth since Myanmar became more politically open in 2010.
“Notably there has been a boom in high-rise buildings constructed from reinforced concrete. Parts of Mandalay and its buildings are especially vulnerable to earthquake shaking because they lie along the floodplain of the Ayerwaddy River.
“Across the river, Sagaing city is much smaller but has also experienced a boom in construction during the past 15 years. Based on the similar earthquake in southern Turkey in February 2023 and the damage that occurred there after years of unregulated construction, it is likely similar damage has occurred in Mandalay and Sagaing and perhaps other cities/towns in central Myanmar.
“The earthquake occurred on the Sagaing Fault – the major tectonic structure that accommodates the northward motion of India and western Myanmar with respect to the rest of SE Asia. The Sagaing Fault passes from the Andaman Sea in the south to the very northern part of Myanmar, close to the eastern corner of the Himalayas. The fault is very similar in scale, movement and seismicity to the San Andreas Fault in California. The geophysical data collected from the earthquake, as well as the epicentral position, is entirely consistent with the earthquake occurring on the Sagaing Fault.
“At magnitude 7.7, today’s earthquake probably propagated well over 100 km and perhaps up to 200 km along the Sagaing Fault. There are reports of damage in the capital city Nay Pyi Taw, which also lies on the Sagaing Fault 250 km south of Mandalay. Although less densely populated than Mandalay, Nay Pyi Taw and the region between it and Mandalay contains clusters of dense towns, many with concrete constructions that may be vulnerable to collapse.
Myanmar experiences frequent earthquakes from a variety of sources, including the Sagaing Fault and other tectonic structures related to its position along the edge of the Indian plate. However, the Sagaing Fault tends to rupture via infrequent, relatively large earthquakes. Those earthquakes initiate at shallow depths (typically about 10-15 km), meaning the seismic energy is not dissipated much by the time it reaches the surface. Along the Sagaing Fault there were several magnitude 7 or greater earthquakes during the 20th Century, including in 1956 near Sagaing, two in 1946 near the northern end of the fault, and two near the southern end of the fault (close to Bago city) in 1930. There is evidence of a very large earthquake in 1839 centred close to Mandalay, which may be the best recent analogue for today’s earthquake.
“Critically, during all previous magnitude 7 or larger earthquakes along the Sagaing Fault, Myanmar was relatively undeveloped, with mostly low-rise timber-framed buildings and brick-built religious monuments. But during the 20th Century there has been substantial development, especially in major cities. In 2012 there was a magnitude 6.8 earthquake about 120 km north of Mandalay, which affected relatively small villages and towns. Despite the moderate size of the earthquake, still there was substantial damage and 26 people died. But today’s earthquake is the first test of modern Myanmar’s infrastructure against a large, shallow-focus earthquake close to its major cities.
“Myanmar has variable awareness of the seismic hazard due to the Sagaing Fault, but it is not as well embedded in society as, for example, the San Andreas Fault in California. General poverty, major political upheval (e.g. the 2021 military coup), alongside other disasters (e.g. Cyclone Nargis in 2008, the Indian Ocean tsunami in 2004) distract the country from concentrating on the more episodic and unpredictable risks from earthquakes. This means that in many cases building design codes are not enforced, and construction happens in areas that could be prone to enhanced seismic risk, for example flood plains and steep slopes.
“Thailand has a generally lower seismic hazard than Myanmar, especially in the central regions (including Bangkok) and southwards. But Thailand’s economy is much more prosperous than Myanmar so building standards are generally higher, better enforced and there is greater preparedness for distant earthquakes like this one, or more local but generally smaller earthquakes like those that happen in northern Thailand.
“Those most vulnerable to this earthquake in Myanmar will include:
– Those living in or near reinforced concrete constructions, especially those with multiple storeys which are more prone to collapse during earthquake shaking.
– Those living in or near older, brick-built religious monuments, for example pagodas and monasteries.
– Those living along the banks of the Ayerwaddy River, which follows, for part of its course, the Sagaing Fault. Landslides along its slopes and liquefaction on its floodbanks can enhance seismic shaking effects.
– Those living in outlying rural areas where access to water, aid and healthcare could become critically difficult in the coming days.
“Aftershocks are incredibly hard to predict but they will be a risk. They will likely continue for days and may continue for years after this earthquake. The pairs of magnitude 7 or greater earthquakes in both 1946 and 1930 are a concern – each propagated along slightly different parts of the fault soon after the initial earthquake, likely the second triggered in response to the first. Again, a similar thing happened in southern Turkey in February 2023, when magnitude 7.8 and 7.5 earthquakes happened within hours of each other on related tectonic structures. That’s relatively unusual behaviour but it’s a risk. More likely there’ll be a series of gradually diminishing earthquakes along the section of the Sagaing Fault that ruptured today, and perhaps on nearby structures, during the coming months.”
“To prepare for any aftershocks it will be critical that survivors aren’t moved into weakened or otherwise vulnerable buildings, that damaged buildings are stabilised quickly, and that there is capacity in the emergency services for additional events.”
Dr Brian Baptie, Seismologist, British Geological Survey (BGS), said:
“Myanmar is an area often exposed to large earthquakes, with over 14 earthquakes with a magnitude of 6 or above occurring in the region over the last 100 years, including a magnitude 6.8 earthquake near Mandalay in 1956 and a 7.6 further north in 1946.
“When you have a large earthquake in an area where there are over a million people, many of them living in vulnerable buildings, the consequences can often be disastrous. From initial reports, that seems likely to be the case here.”
“The magnitude 7.7 earthquake appears to have ruptured a 200 km section of the Sagaing Fault, a major North-South fault that separates the India plate and the Sunda Plate. The rupture propagated from North to South over a period of just over a minute, with slip of up to 5 metres in places. The earthquake resulted in intense ground shaking, with at least 2.8 million people in Myanmar exposed to severe or violent shaking, with most of the population in the region living in buildings that are constructed from timber and unreinforced brick masonry, and that are vulnerable to earthquake shaking.
“Earthquake hazard is high along the Indo-Burmese arc and large earthquakes have occurred in this region over the last 100 years or so. These include a magnitude 6.8 earthquake near Mandalay in 1956 that caused significant damage. In 1946 there was a magnitude 7.6 earthquake in the north of the Sagaing region and in 1912 a magnitude 7.8 further south.”
Dr Mehdi Kashani, Associate Professor in Structures, Design, and Earthquake Engineering, University of Southampton, said:
“Today’s earthquake had a magnitude of 7.7 and occurred at a depth of 10.0 km, classifying it as a shallow earthquake, which tends to be destructive. The epicentre was located just west of Mandalay, within the Sagaing Fault zone. The structural damage observed is consistent with patterns seen in previous significant earthquakes in the region.
“Myanmar is located at the convergence of several tectonic plates, including the Indian Plate, the Burma microplate, and the Sunda Plate, making it a seismically active region. The Sagaing Fault, a major tectonic boundary, runs north to south through the country and plays a significant role in its earthquake risk.
“Earthquakes are relatively common in Myanmar. According to the United States Geological Survey, six major earthquakes with magnitudes of 7.0 or higher struck near the Sagaing Fault between 1930 and 1956.”
Prof Ian Main, Professor of Seismology and Rock Physics, University of Edinburgh, said:
What do we know about the situation?
“The damage is likely to be very severe near the epicentre and along the fault rupture in a north-south direction. The area of likely severe damage is indicated in red in the interactive map from the USGS earthquake website [1], with the star showing the epicentre location. Maps like this will be updated as more reports of actual damage come in, but it is a significant concern that there are few felt reports in the areas near the epicentre as yet.
“The impact is likely to be severe. Based on the estimated intensity of ground shaking above, and maps of population density and vulnerability of buildings, the USGS ‘PAGER’ forecast loss is, sadly, most likely to be in the range 10,000-100,000 fatalities and some 6-70% of the GDP of Myanmar [2].
“The earthquake occurred to the east of an arcuate band of seismicity (grey dots) shown in the interactive map. The fault rupture strikes near due north, with a vertical dip and a horizontal shear motion along strike that is consistent with the oblique convergence of the Indian plate from the south-west. The sense of slip is right-lateral, meaning the crust to the east of the rupture moved south and the western side moved to the north, with negligible vertical displacement. Similar strike-slip earthquakes are found in a curve extending as far south as Sumatra. The earthquake is therefore very much consistent with current understanding of the relationship between tectonics and seismicity in the area.
Are earthquakes common in the region?
“Yes, though relatively less common in the area affected today [1]. Nevertheless the USGS reports ‘Between 1930 and 1956, six M7.0+ earthquakes occurred near the right-lateral Sagaing Fault, resulting in severe damage in Myanmar including the generation of landslides, liquefaction and the loss of 610 lives’.
How does this earthquake compare to previous ones in the region?
“It is not unusual given the history above, though it is historically one of the most severe.
How well prepared was Myanmar and Thailand (and other affected countries) for an earthquake of this size?
“Myanmar published a National building code in 2020 [3] but it is not clear how many legacy buildings would be vulnerable, or the extent to which the codes have been enforced since then.
Who might be particularly vulnerable to the impacts of this earthquake and why?
“The UN analysed the impact of natural disasters of all kinds, and concluded that poverty, poor governance and poorly planned urban development are the major controlling factors [4].
Are there concerns of aftershocks and what can be done to prepare for them?
“Yes. The USGS posts operational aftershock forecasts [5], though not yet for this earthquake. Such operational forecasts, along with interactive maps as shown above, help the authorities plan the emergency response and to communicate and manage the risk of future earthquakes in the same sequence.”
Prof David Rothery, Professor of Planetary Geosciences, Open University, said:
“This was a large earthquake at shallow depth on a fault that runs north-south through Myanmar that allows the Indian tectonic plate to slide past as it travels northward into the Himalayas. The last comparable quake nearby was a magnitude 7.0 event in January 1990. It is possible to construct bridges and buildings to withstand earthquake shaking of this sort, which will have been made worse by the shallowness of the initial rupture and the unconsolidated nature of the ground in the river valley, which would shake more strongly than bedrock. From what I’ve seen, most modern buildings survived, but some collapsed, as did at least one bridge across the Irrawaddy – those may have been substandard or just unlucky.”
Dr Leslie Mabon, Senior Lecturer in Environmental Systems, The Open University, said:
“This earthquake has only just happened, and information about damage and casualties – especially from Myanmar – is still emerging. However, as with any event like this anywhere in the world, it’s important to remember that there’s no such thing as a natural disaster. In any country, a very wide range of social and political factors such as income, access to information, building codes, and emergency response systems all influence who survives, and who is exposed to harm, from any kind of natural hazard.
“What will be especially important to watch out for in the coming weeks and days is how quickly help gets to the poorest and most vulnerable people, as well as who and where has been affected most badly.”
Prof Bill McGuire, Professor Emeritus of Geophysical & Climate Hazards, University College London (UCL), said:
“Myanmar is one of the most seismically active countries in the world, so this quake is not a surprise. It looks to have occurred on the major Sagaing Fault, which marks the boundary between two tectonic plates, and which runs north – south close to a number of large population centres.
“This is probably the biggest earthquake on the Myanmar mainland in three quarters of a century, and a combination of size and very shallow depth will maximise the chances of damage. It is highly likely that build quality will generally not be high enough to survive this level of shaking, and casualty numbers will almost certainly climb significantly as more becomes known of the scale of the disaster.
“There has already been one sizeable aftershock and more can be expected. This will threaten the collapse of weakened buildings and make the jobs of rescue workers that much more challenging”
Prof Joanna Faure Walker, Professor of Earthquake Geology and Disaster Risk Reduction, University College London (UCL), said:
“Myanmar is no stranger to earthquakes. The plate boundary between the India Plate and Eurasia Plate runs approximately north-south, cutting through the middle of the country. These two plates move past each other as they are moving at different rates along a transform plate boundary (a bit like the San Andreas Fault in the south west of the United States). Although such strike slip earthquakes are of smaller magnitude than the largest earthquakes seen in subduction zones, like to the south in Sumatra, they can still reach magnitudes 7 to 8 and cause severe destruction, as we are seeing in the March 2025 earthquake.”
“With earthquake waves, the greater the amplitude of the waves, generally the greater the damage. The amplitude of the waves decrease with distance from the rupture. Higher frequency waves’ amplitudes decrease faster than lower frequency waves so far away from the source it is mostly the low frequency waves causing the damage. The lower frequency waves tend to cause more damage to taller buildings because the natural frequency of buildings is approximately ten divided by the number of storeys (the exact value will depend on the height of the storeys).”
Dr Roger Musson, Honorary Research Fellow, British Geological Survey (BGS), said:
“Large earthquakes in this region are rare but not unknown, the last similar event being in 1956, more or less beyond living memory. This means that buildings are unlikely to be designed against seismic forces, and therefore are more vulnerable when an earthquake like this occurs, resulting in more damage and higher casualties. The ultimate cause of the earthquake is the northward movement of the Indian Plate, which produces a tearing effect along N-S trending vertical faults.”
“The design of buildings to resist earthquakes is not to prevent all damage, which would be impossible, but to control where in a building damage occurs – damage is allowed but what has to be prevented is collapse. Photos coming out of Myanmar show cases of complete collapse, which demonstrates that they have not been constructed following the principles of earthquake resistant design. This suggests the casualty rate may be high.”
Prof Ilan Kelman, Professor of Disasters and Health, Institute for Risk and Disaster Reduction (IRDR), University College London (UCL), said:
“Getting humanitarian relief into the worst-affected areas of Burma / Myanmar might not be politically easy. In 2008, Cyclone Nargis killed over 130,000 people in the country. The government took days to accept significant aid and then inhibited its delivery.
“For ‘disaster diplomacy’ to work – supporting disaster-affected people in areas with violent or political conflict – the world and the disaster-struck authorities must cooperate. Many governments running Burma / Myanmar have been highly controlling, including since the February 2021 military coup. Helping people in need without helping an oppressive government is a tricky situation for aid donors to navigate, not helped by the reported damage to transportation and communication systems.
“The usual mantra is that ‘Earthquakes don’t kill people; collapsing infrastructure does’. Governments are responsible for planning regulations and building codes. This disaster exposes what governments of Burma / Myanmar failed to do long before the earthquake which would have saved lives during the shaking.”
Declared interests
Dr Christian Málaga-Chuquitaype “No conflicts to declare”
Dr Roberto Gentile “I have no conflicts of interest”
Dr Rebecca Bell No conflicts to declare
Prof Ian Main “No conflicts”
Dr Ian Watkinson “No conflicts to declare”
Dr Mehdi Kashani “I can confirm that I have to conflict of interest”
Dr Roger Musson “I have no involvement in the area”
Dr Leslie Mabon “None to declare”
Prof Bill McGuire “No interests to declare”
Prof Joanna Faure Walker “None to declare”
Prof Ilan Kelman “Ilan has been researching disaster diplomacy since 1999.”
For all other experts, no reply to our request for DOIs was received.